What Is the Keto Flu?

What Is the Keto Flu?

The keto flu can be a little confusing and, for those who aren't expecting it, downright spooky. Diets are supposed to make you healthier, not sicker, right? While that's generally a good rule of thumb, the keto flu is a pretty natural bodily response to cutting carbs and loading up on fat. Let's take a closer look.

Your body’s primary and preferred fuel is glucose derived from carbs, so when it makes the sudden switch to running on ketones, it can get a little pissy. The keto flu is a series of symptoms including brain fog, headaches, nausea, and fatigue, along with bad breath, sweat, and urine. The unpleasant flu-like symptoms are a result of your brain needing to adjust to the new source of energy while dealing with plummeting electrolyte levels (that is sodium, magnesium, and potassium) thanks to the drop in water weight.

Meanwhile, those weird smells are typically due to a byproduct of ketone metabolism (a.k.a. acetone) seeping out of your body. Thankfully (for you and those around you), most people report feeling better within a few days, or up to a week, so as long as you stick with the keto diet through the rough patch, you’ll be in the clear. And once you make it through those bouts of nausea and weird smells, you'll start seeing the many health benefits of keto.